Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 63
Filtrar
1.
Chemistry ; 22(38): 13705-14, 2016 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-27356278

RESUMO

A 3D metal-organic framework (MOF) having single-molecule magnet (SMM) linkers was prepared in crystalline form by using a tetrairon(III) complex functionalised with two divergent pyridyl groups, namely [Fe4 (pPy)2 (dpm)6 ] (1; H3 pPy=2-(hydroxymethyl)-2-(pyridin-4-yl)propane-1,3-diol, Hdpm=dipivaloylmethane). Reaction of 1 with silver(I) perchlorate afforded {[Fe4 (pPy)2 (dpm)6 ]2 Ag}ClO4 (2), which crystallises in a cubic face-centred lattice and exhibits two interlocked diamondoid networks. In 2, the SMMs act as linear ditopic synthons, and silver(I) ions as tetrahedral nodes coordinated by four pyridyl nitrogen atoms. The magnetic properties of 1 (S=5 and D≈-0.4 cm(-1) in the ground spin state) are largely preserved in 2, which shows slow magnetic relaxation with an anisotropy barrier of Ueff /kB =11.46(10) K in zero field and 14.25(8) K in an applied field of 1 kOe. However, crystal symmetry triggers highly noncollinear magnetic anisotropy contributions oriented at 109.47° from each other along the threefold axes of AgN4 tetrahedra, a unique scenario fully confirmed by a single-crystal cantilever torque magnetometry investigation. Magnetisation curves down to 0.03 K demonstrated the occurrence of a wide hysteresis loop when the magnetic field was swept along one of the four Ag-N bonds. By symmetry, the crystalline compound can then be persistently magnetised parallel or antiparallel to the four main diagonals of the unit cell, although the crystals have no overall second-order anisotropy.

2.
Chemistry ; 21(34): 12171-80, 2015 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-26178233

RESUMO

Compounds [Fe3 Ln(tea)2 (dpm)6 ] (Fe3 Ln; Ln= Tb-Yb, H3 tea=triethanolamine, Hdpm=dipivaloylmethane) were synthesized as lanthanide(III)-centered variants of tetrairon(III) single-molecule magnets (Fe4 ) and isolated in crystalline form. Compounds with Ln=Tb-Tm are isomorphous and show crystallographic threefold symmetry. The coordination environment of the rare earth, given by two tea(3-) ligands, can be described as a bicapped distorted trigonal prism with D3 symmetry. Magnetic measurements showed the presence of weak ferromagnetic Fe⋅⋅⋅Ln interactions for derivatives with Tb, Dy, Ho, and Er, and of weak antiferromagnetic or negligible coupling in complexes with Tm and Yb. Alternating current susceptibility measurements showed simple paramagnetic behavior down to 1.8 K and for frequencies reaching 10000 Hz, despite the easy-axis magnetic anisotropy found in Fe3 Dy, Fe3 Er, and Fe3 Tm by single-crystal angle-resolved magnetometry. Relativistic quantum chemistry calculations were performed on Fe3 Ln (Ln=Tb-Tm): the ground J multiplet of Ln(3+) ion is split by the crystal field to give a ground singlet state for Tb and Tm, and a doublet for Dy, Ho, and Er with a large admixture of mJ states. Gyromagnetic factors result in no predominance of gz component along the threefold axis, with comparable gx and gy values in all compounds. It follows that the environment provided by the tea(3-) ligands, though uniaxial, is unsuitable to promote slow magnetic relaxation in Fe3 Ln species.

3.
Angew Chem Int Ed Engl ; 54(30): 8777-82, 2015 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-26096860

RESUMO

Tetrairon(III) single-molecule magnets [Fe4(pPy)2(dpm)6] (1) (H3pPy=2-(hydroxymethyl)-2-(pyridin-4-yl)propane-1,3-diol, Hdpm=dipivaloylmethane) have been deliberately organized into supramolecular chains by reaction with Ru(II)Ru(II) or Ru(II)Ru(III) paddlewheel complexes. The products [Fe4(pPy)2(dpm)6][Ru2(OAc)4](BF4)x with x=0 (2 a) or x=1 (2 b) differ in the electron count on the paramagnetic diruthenium bridges and display hysteresis loops of substantially different shape. Owing to their large easy-plane anisotropy, the s=1 diruthenium(II,II) units in 2 a act as effective s(eff)=0 spins and lead to negligible intrachain communication. By contrast, the mixed-valent bridges (s=3/2, s(eff)=1/2) in 2 b introduce a significant exchange bias, with concomitant enhancement of the remnant magnetization. Our results suggest the possibility to use electron transfer to tune intermolecular communication in redox-responsive arrays of SMMs.

4.
Phys Chem Chem Phys ; 16(32): 17220-30, 2014 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-25014192

RESUMO

Single-crystal torque magnetometry performed on weakly-coupled polynuclear systems provides access to a complete description of single-site anisotropy tensors. Variable-temperature, variable-field torque magnetometry was used to investigate triiron(III) complex [Fe3La(tea)2(dpm)6] (Fe3La), a lanthanum(III)-centred variant of tetrairon(III) single molecule magnets (Fe4) (H3tea = triethanolamine, Hdpm = dipivaloylmethane). Due to the presence of the diamagnetic lanthanoid, magnetic interactions among iron(III) ions (si = 5/2) are very weak (<0.1 cm(−1)) and the magnetic response of Fe3La is predominantly determined by single-site anisotropies. The local anisotropy tensors were found to have Di > 0 and to be quasi-axial with |Ei/Di| ~ 0.05. Their hard axes form an angle of approximately 70° with the threefold molecular axis, which therefore corresponds to an easy magnetic direction for the molecule. The resulting picture was supported by a High Frequency EPR investigation and by DFT calculations. Our study confirms that the array of peripheral iron(III) centres provides substantially noncollinear anisotropy contributions to the ground state of Fe4 complexes, which are of current interest in molecular magnetism and spintronics.

5.
Eur Heart J ; 34(3): 201-10, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23136403

RESUMO

AIMS: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a major cause of juvenile sudden death and is characterized by fibro-fatty replacement of the right ventricle. Mutations in several genes encoding desmosomal proteins have been identified in ARVC. We speculated that αT-catenin, encoded by CTNNA3, might also carry mutations in ARVC patients. Alpha-T-catenin binds plakophilins and this binding contributes to the formation of the area composita, which strengthens cell-cell adhesion in contractile cardiomyocytes. METHODS AND RESULTS: We used denaturing high-performance liquid chromatography and direct sequencing to screen CTNNA3 in 76 ARVC patients who did not carry any mutations in the desmosomal genes commonly mutated in ARVC. Mutations c.281T > A (p.V94D) and c.2293_2295delTTG (p.del765L) were identified in two probands. They are located in important domains of αT-catenin. Yeast two-hybrid and cell transfection studies showed that the interaction between the p.V94D mutant protein and ß-catenin was affected, whereas the p.del765L mutant protein showed a much stronger dimerization potential and formed aggresomes in HEK293T cells. CONCLUSION: These findings might point to a causal relationship between CTNNA3 mutations and ARVC. This first report on the involvement of an area composita gene in ARVC shows that the pathogenesis of this disease extends beyond desmosomes. Since the frequency of CTNNA3 mutations in ARVC patients is not rare, systematic screening for this gene should be considered to improve the clinical management of ARVC families.


Assuntos
Displasia Arritmogênica Ventricular Direita/genética , Morte Súbita Cardíaca/etiologia , Deleção de Genes , Mutação de Sentido Incorreto/genética , alfa Catenina/genética , Adulto , Arritmias Cardíacas/genética , Displasia Arritmogênica Ventricular Direita/metabolismo , Estudos de Casos e Controles , Eletrocardiografia , Feminino , Heterozigoto , Humanos , Masculino , Linhagem , alfa Catenina/metabolismo
6.
J Surg Oncol ; 106(1): 17-23, 2012 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-22258756

RESUMO

BACKGROUND: Free peritoneal tumor cells (FPTC) derive from the detachment of primary cancer and may result in peritoneal carcinomatosis. Since peritoneal lavage cytology has low sensitivity in detecting FPTC, our aim was to estimate the clinical relevance of FPTC detected using an approach based on multiple molecular techniques. MATERIALS AND METHODS: Samples of peritoneal lavage were collected from 27 gastric and 48 colorectal cancer patients. FPTC recovery and detection from peritoneal washes was performed by cytological examination and immunomagnetic enrichment for epithelial cells followed by immunofluorescence analysis for epithelial marker EpCAM/CD326 and carcinoembryonic antigen (CEA). CEA and CK20 mRNA levels were quantified using a real-time qRT-PCR system. RESULTS: For gastric carcinoma the FPTC positivity rate acquired by cytology, immunofluorescence and qRT-PCR was 14.8%, 14.8%, and 78% and for colorectal carcinoma was 0%, 17%, and 42%, respectively. qRT-PCR positivity was correlated with a poor cancer-specific survival and time-to-recurrence rates in both gastric and colorectal carcinoma. CONCLUSIONS: Epithelial immunoenrichment and immunofluorescence analysis allows unequivocal identification of the FPTC. The real time qRT-PCR showed higher sensitivity for the detection of CEA and CK20 mRNA levels and confirmed its prognostic value in gastrointestinal cancers.


Assuntos
Biomarcadores Tumorais/análise , Neoplasias Colorretais/patologia , Cavidade Peritoneal/patologia , Neoplasias Gástricas/patologia , Idoso , Idoso de 80 Anos ou mais , Antígenos de Neoplasias/análise , Antígeno Carcinoembrionário/análise , Moléculas de Adesão Celular/análise , Neoplasias Colorretais/química , Intervalo Livre de Doença , Molécula de Adesão da Célula Epitelial , Feminino , Imunofluorescência , Humanos , Estimativa de Kaplan-Meier , Queratina-20/análise , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Estadiamento de Neoplasias , Lavagem Peritoneal , Modelos de Riscos Proporcionais , Reação em Cadeia da Polimerase em Tempo Real , Neoplasias Gástricas/química
7.
World J Surg ; 36(1): 24-30, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22089921

RESUMO

BACKGROUND: Cardiovascular disease is the leading cause of perioperative death in surgical patients. A variety of clinical scoring systems have been developed to predict adverse cardiovascular events. B-type natriuretic peptide (BNP) is a sensitive and specific predictor of left ventricular systolic dysfunction and predicts first cardiovascular event and death in the general population. We present a prospective, single-center, observational cohort study of patients undergoing major abdominal surgery and evaluate the role of BNP in predicting adverse cardiac events. METHOD: A total of 205 patients were included in the study. All patients were assessed by a cardiological clinical evaluation, a 12-lead ECG report, and a preoperative and postoperative blood sample for plasmatic BNP assessment. The primary end point was the predictive power of preoperative BNP levels for adverse cardiac events until 30 days after discharge. RESULTS: Thirty-one of 205 (15%) patients had adverse cardiac events in the postoperative period up to 30 days after discharge. Five patients (2.4%) of these died of cardiac events. Preoperative BNP values were significantly increased in the 31 patients compared to the other patients in the postoperative period [mean = 112.93 pg/ml (range = 5-2,080) vs. 178.99 pg/ml (range = 5-3,980); median = 117 vs. 23 pg/ml; 95% CI = 49-181; p < 0.0001]. At logistic regression, a preoperative BNP value of >36 pg/ml was the only effective predictor of adverse cardiac events. CONCLUSION: We have demonstrated that elevated preoperative BNP levels are independent predictors of adverse cardiac events in a cohort of patients undergoing major abdominal surgery in a general surgery department, and this is the first study about this specific cohort of patients.


Assuntos
Abdome/cirurgia , Doenças Cardiovasculares/etiologia , Técnicas de Apoio para a Decisão , Peptídeo Natriurético Encefálico/sangue , Complicações Pós-Operatórias , Procedimentos Cirúrgicos Operatórios , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/mortalidade , Feminino , Seguimentos , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/mortalidade , Período Pós-Operatório , Período Pré-Operatório , Prognóstico , Estudos Prospectivos , Curva ROC , Medição de Risco/métodos , Adulto Jovem
8.
J Clin Med ; 11(3)2022 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-35160159

RESUMO

Surgical treatment of hemorrhoidal disease (HD) in inflammatory bowel disease (IBD) has been considered to be potentially harmful, but the evidence for this is poor. Therefore, a systematic review of the literature was undertaken to reappraise the safety and effectiveness of surgical treatments in this special circumstance. A MEDLINE, Web of Science, Scopus, and Cochrane Library search was performed to retrieve studies reporting the outcomes of surgical treatment of HD in patients with Crohn's disease (CD) and ulcerative colitis (UC). From a total of 2072 citations, 10 retrospective studies including 222 (range, 2-70) patients were identified. Of these, 119 (54%) had CD and 103 (46%) UC. Mean age was between 41 and 49 years (range 14-77). Most studies lacked information on the interval between surgery and the onset of complications. Operative treatments included open or closed hemorrhoidectomy (n = 156 patients (70%)), rubber band ligation (n = 39 (18%)), excision or incision of thrombosed hemorrhoid (n = 14 (6%)), and doppler-guided hemorrhoidal artery ligation (DG-HAL, n = 13 (6%)). In total, 23 patients developed a complication (pooled prevalence, 9%; (95%CI, 3-16%)), with a more than two-fold higher rate in patients with CD compared to UC (11% (5-16%) vs. 5% (0-13%), respectively). Despite the low quality evidence, surgical management of HD in IBD and particularly in CD patients who have failed nonoperative therapy should still be performed with caution and limited to inactive disease. Further studies should determine whether advantages in terms of safety and effectiveness with the use of non-excisional techniques (e.g., DG-HAL) can be obtained in this patient population.

9.
Circulation ; 121(13): 1533-41, 2010 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-20172911

RESUMO

BACKGROUND: In 1994, an International Task Force proposed criteria for the clinical diagnosis of arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) that facilitated recognition and interpretation of the frequently nonspecific clinical features of ARVC/D. This enabled confirmatory clinical diagnosis in index cases through exclusion of phenocopies and provided a standard on which clinical research and genetic studies could be based. Structural, histological, electrocardiographic, arrhythmic, and familial features of the disease were incorporated into the criteria, subdivided into major and minor categories according to the specificity of their association with ARVC/D. At that time, clinical experience with ARVC/D was dominated by symptomatic index cases and sudden cardiac death victims-the overt or severe end of the disease spectrum. Consequently, the 1994 criteria were highly specific but lacked sensitivity for early and familial disease. METHODS AND RESULTS: Revision of the diagnostic criteria provides guidance on the role of emerging diagnostic modalities and advances in the genetics of ARVC/D. The criteria have been modified to incorporate new knowledge and technology to improve diagnostic sensitivity, but with the important requisite of maintaining diagnostic specificity. The approach of classifying structural, histological, electrocardiographic, arrhythmic, and genetic features of the disease as major and minor criteria has been maintained. In this modification of the Task Force criteria, quantitative criteria are proposed and abnormalities are defined on the basis of comparison with normal subject data. CONCLUSIONS: The present modifications of the Task Force Criteria represent a working framework to improve the diagnosis and management of this condition. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00024505.


Assuntos
Displasia Arritmogênica Ventricular Direita/diagnóstico , Displasia Arritmogênica Ventricular Direita/terapia , Ecocardiografia , Eletrocardiografia Ambulatorial , Imageamento por Ressonância Magnética , Biópsia , Morte Súbita Cardíaca , Humanos , Guias de Prática Clínica como Assunto , Padrões de Referência , Sensibilidade e Especificidade
10.
Eur Heart J ; 31(7): 806-14, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20172912

RESUMO

BACKGROUND: In 1994, an International Task Force proposed criteria for the clinical diagnosis of arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) that facilitated recognition and interpretation of the frequently nonspecific clinical features of ARVC/D. This enabled confirmatory clinical diagnosis in index cases through exclusion of phenocopies and provided a standard on which clinical research and genetic studies could be based. Structural, histological, electrocardiographic, arrhythmic, and familial features of the disease were incorporated into the criteria, subdivided into major and minor categories according to the specificity of their association with ARVC/D. At that time, clinical experience with ARVC/D was dominated by symptomatic index cases and sudden cardiac death victims-the overt or severe end of the disease spectrum. Consequently, the 1994 criteria were highly specific but lacked sensitivity for early and familial disease. METHODS AND RESULTS: Revision of the diagnostic criteria provides guidance on the role of emerging diagnostic modalities and advances in the genetics of ARVC/D. The criteria have been modified to incorporate new knowledge and technology to improve diagnostic sensitivity, but with the important requisite of maintaining diagnostic specificity. The approach of classifying structural, histological, electrocardiographic, arrhythmic, and genetic features of the disease as major and minor criteria has been maintained. In this modification of the Task Force criteria, quantitative criteria are proposed and abnormalities are defined on the basis of comparison with normal subject data. CONCLUSIONS: The present modifications of the Task Force Criteria represent a working framework to improve the diagnosis and management of this condition. Clinical Trial Registration clinicaltrials.gov Identifier: NCT00024505.


Assuntos
Displasia Arritmogênica Ventricular Direita/diagnóstico , Displasia Arritmogênica Ventricular Direita/genética , Displasia Arritmogênica Ventricular Direita/terapia , Biópsia , Eletrocardiografia , Genótipo , Humanos , Angiografia por Ressonância Magnética/normas , Miocárdio/patologia , Fenótipo , Guias de Prática Clínica como Assunto , Sensibilidade e Especificidade
11.
Eur J Surg Oncol ; 47(11): 2893-2899, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34052038

RESUMO

BACKGROUND: Mixed adeno-neuroendocrine carcinomas (MANEC) are a subgroup of mixed neuroendocrine non-neuroendocrine neoplasms (MiNEN) described as mixed neoplasms containing dual neuroendocrine and non-neuroendocrine components. The aim of this study was to appraise the prevalence of MANEC in the lower gastrointestinal (GI) tract and provide reliable estimates of survival. METHOD: A systematic review was undertaken in accordance with PRISMA guidelines using PubMed, Embase, Cochrane Library of Systematic Review, Web of Science, and Scopus databases, and a Bayesian hierarchical survival pooled analysis was performed. RESULTS: Of 182 unique records identified, 71 studies reporting on 752 patients met the inclusion criteria. Mean age was 64.2 ± 13.6, with a male-to-female ratio of 1.25. Overall, 60.3% of MANEC were located in the appendix, 29.3% in the colon, and 10.4% in the anorectum. More than a quarter (29%) of patients had stage IV disease at diagnosis, with higher prevalence in appendiceal than colonic and anorectal primaries. More than 80% had a high-grade (G3) endocrine component. Of the 152 patients followed up for a median of 20 months (interquartile range limits, 16.5-32), median overall survival was 12.3 months (95% credible interval [95%CrI], 11.3-13.7), with a 1.12 [95%CrI, 0.67-1.83] age-adjusted hazard ratio between metastatic and non-metastatic MANEC. Stage IV disease at diagnosis was more prognostically unfavorable in cases of colonic compared to anorectal origin. CONCLUSION: MANEC is a clinically aggressive pathological entity. The results of this study provide new insights for the understanding of tumor location within the lower GI tract and its prognosis in terms of overall survival.


Assuntos
Carcinoma Neuroendócrino/mortalidade , Carcinoma Neuroendócrino/patologia , Neoplasias Gastrointestinais/mortalidade , Neoplasias Gastrointestinais/patologia , Trato Gastrointestinal Inferior/patologia , Teorema de Bayes , Humanos , Estadiamento de Neoplasias , Prognóstico , Análise de Sobrevida
12.
Lancet ; 373(9671): 1289-300, 2009 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-19362677

RESUMO

Arrhythmogenic right ventricular cardiomyopathy is a rare inherited heart-muscle disease that is a cause of sudden death in young people and athletes. Causative mutations in genes encoding desmosomal proteins have been identified and the disease is nowadays regarded as a genetically determined myocardial dystrophy. The left ventricle is so frequently involved as to support the adoption of the broad term arrhythmogenic cardiomyopathy. Clinical diagnosis can be achieved by demonstrating function and structure changes of the right ventricle, electrocardiogram depolarisation and repolarisation abnormalities, ventricular arrhythmias, and fibrofatty replacement through endomyocardial biopsy. Although specific, the standardised diagnostic criteria lack sensitivity for early disease and their primary application remains in establishing the diagnosis in probands. However, the main clinical targets are early detection of concealed forms and risk stratification for preventive strategies, which include physical exercise restriction, antiarrhythmic drugs, and implantable cardioverter-defibrillator therapy. Cascade genetic screening of family members of gene-positive probands allows the identification of asymptomatic carriers who would require lifelong follow-up due to the age-related penetrance.


Assuntos
Displasia Arritmogênica Ventricular Direita/diagnóstico , Displasia Arritmogênica Ventricular Direita/terapia , Antagonistas Adrenérgicos beta/uso terapêutico , Assistência ao Convalescente , Antiarrítmicos/uso terapêutico , Displasia Arritmogênica Ventricular Direita/epidemiologia , Displasia Arritmogênica Ventricular Direita/genética , Biópsia , Causalidade , Causas de Morte , Morte Súbita Cardíaca/etiologia , Morte Súbita Cardíaca/prevenção & controle , Desfibriladores Implantáveis , Progressão da Doença , Diagnóstico Precoce , Eletrocardiografia , Triagem de Portadores Genéticos , Testes Genéticos , Humanos , Miócitos Cardíacos/ultraestrutura , Doenças Raras , Medição de Risco , Sensibilidade e Especificidade
13.
J Gastrointest Surg ; 24(10): 2336-2348, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32583324

RESUMO

BACKGROUND: In literature, percentages of pathologic complete response (pCR) in patients presenting with resectable (RES), borderline resectable (BLR) or locally advanced (LA) pancreatic cancer (PaC) after neoadjuvant treatment (NADT) are variable, ranging 0-33%. Those data come mostly from retrospective reviews of single centres. The objective of this systematic review is to assess the incidence of pCR. METHODS: Following the criteria of the PRISMA statement, a literature search was conducted looking for prospective papers focusing on neoadjuvant treatment in PaC. Retrospective papers, other than ductal carcinoma histologies and trials including metastatic patients, were excluded from the present review. Data extraction was carried out by 3 independent investigators. Meta-analysis was performed with ProMeta3 Software (Internovi, 2015). PROSPERO registry: CRD42018095641. RESULTS: The literature search of Embase, Cochrane and Medline with the terms "neoadjuvant OR preoperative", "pancreatic OR pancreas" and "cancer OR adenocarcinoma OR tumor" led to the identification of 3128 papers. We restricted the search to humans, last 10 years and English language articles resulting in 1158 eligible articles to review. Extended paper revision led to the inclusion of 27 papers. Complete pathologic response ranged 0-11.11%, at the meta-analysis 4% (95% CI 3-5%), in prospective studies 0-9.09% and in prospective databases 1.63-11.11%. CONCLUSIONS: Pathologic complete response in pancreatic cancer is actually infrequent: high-quality studies provide a more reliable picture of neoadjuvant effects, high rates of pCR are reported in selected retrospective studies but it is overestimated.


Assuntos
Neoplasias Pancreáticas , Humanos , Terapia Neoadjuvante , Neoplasias Pancreáticas/terapia , Estudos Prospectivos , Estudos Retrospectivos
14.
Eur Heart J ; 29(22): 2760-71, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18819962

RESUMO

AIMS: To provide a standardized endomyocardial biopsy (EMB) protocol and diagnostic quantitative parameters for arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D). The Task Force criteria for the in vivo diagnosis of ARVC/D include tissue characterization by EMB as a major criterion. METHODS AND RESULTS: EMBs were simulated in vitro with a Cordis bioptome in explanted hearts from six groups: diffuse (n = 10) and segmental (n = 10) ARVC/D, dilated cardiomyopathy (DC) (n = 10), controls (n = 10), adipositas cordis (n = 10), elderly >80 years (n = 10). Sampling sites were the RV inferior-subtricuspid, antero-apical, and mid-outflow tract (RVOT), the septum, and the left ventricle (LV). Histomorphometry was performed to evaluate the amount of myocardium and fibrous and fatty tissues. Myocyte diameters and abnormalities were also assessed. By selecting a 95% specificity, the ARVC/D diagnostic cut-offs on cumulative RV EMB samples are myocardium <59%, fibrosis >31% and fat >22% (80, 50, and 50% sensitivity, respectively). By excluding elderly and obese people groups a lower cut-off for fat was found (>9%). A high variability between different RV sampling sites was observed; the antero-apical was the most informative region although fat at this level is non-specific. No useful diagnostic cut-off for fatty tissue was identified at the antero-apical and RVOT area. No significant difference was found for any tissue parameter either in septal or in LV EMB. Increased RV myocyte diameters and cytological changes were detected in ARVC/D and DC. CONCLUSION: The residual myocardium is the main diagnostic morphometric parameter in ARVC/D, whereas fat at the apex is non-specific. Sensitivity and specificity vary according to the RV region. Target sampling of the triangle of dysplasia is required, although only a single region is often informative, emphasizing the usefulness of imaging-guided EMB. There is no diagnostic value of either septal or LV EMB. Cardiomyopathic changes of the myocytes also appear important for establishing a pathological diagnosis.


Assuntos
Tecido Adiposo/patologia , Displasia Arritmogênica Ventricular Direita/patologia , Fibrose Endomiocárdica/patologia , Ventrículos do Coração/patologia , Miocárdio/patologia , Função Ventricular Direita/fisiologia , Tecido Adiposo/fisiopatologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Displasia Arritmogênica Ventricular Direita/fisiopatologia , Biópsia/métodos , Fibrose Endomiocárdica/fisiopatologia , Estudos de Avaliação como Assunto , Humanos , Pessoa de Meia-Idade , Sensibilidade e Especificidade
15.
Circulation ; 113(9): 1171-9, 2006 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-16505173

RESUMO

BACKGROUND: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited cardiomyopathy characterized by progressive myocardial atrophy with fibrofatty replacement. The recent identification of causative mutations in plakoglobin, desmoplakin (DSP), and plakophilin-2 (PKP2) genes led to the hypothesis that ARVC is due to desmosomal defects. Therefore, desmoglein-2 (DSG2), the only desmoglein isoform expressed in cardiac myocytes, was screened in subjects with ARVC. METHODS AND RESULTS: In a series of 80 unrelated ARVC probands, 26 carried a mutation in DSP (16%), PKP2 (14%), and transforming growth factor-beta3 (2.5%) genes; the remaining 54 were screened for DSG2 mutations by denaturing high-performance liquid chromatography and direct sequencing. Nine heterozygous DSG2 mutations (5 missense, 2 insertion-deletions, 1 nonsense, and 1 splice site mutation) were detected in 8 probands (10%). All probands fulfilled task force criteria for ARVC. An endomyocardial biopsy was obtained in 5, showing extensive loss of myocytes with fibrofatty tissue replacement. In 3 patients, electron microscopy investigation was performed, showing intercalated disc paleness, decreased desmosome number, and intercellular gap widening. CONCLUSIONS: This is the first investigation demonstrating DSG2 gene mutations in a significant number of ARVC-unrelated probands. Cardiac phenotype is characterized clinically by typical ARVC features with frequent left ventricular involvement and morphologically by fibrofatty myocardial replacement and desmosomal remodeling. The presence of mutations in desmosomal encoding genes in 40% of cases confirms that many forms of ARVC are due to alterations in the desmosome complex.


Assuntos
Displasia Arritmogênica Ventricular Direita/genética , Desmogleína 2/genética , Mutação , Adolescente , Adulto , Displasia Arritmogênica Ventricular Direita/etiologia , Displasia Arritmogênica Ventricular Direita/patologia , Biópsia , Criança , Análise Mutacional de DNA , Desmossomos/genética , Desmossomos/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Miocárdio/patologia , Placofilinas/genética , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta2
16.
BMC Med Genet ; 8: 65, 2007 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-17963498

RESUMO

BACKGROUND: Mutations in genes encoding desmosomal proteins have been reported to cause arrhythmogenic right ventricular cardiomyopathy (ARVC), an autosomal dominant disease characterised by progressive myocardial atrophy with fibro-fatty replacement. We screened 54 ARVC probands for mutations in desmocollin-2 (DSC2), the only desmocollin isoform expressed in cardiac tissue. METHODS: Mutation screening was performed by denaturing high-performance liquid chromatography and direct sequencing. To evaluate the pathogenic potentials of the DSC2 mutations detected in patients affected with ARVC, full-length wild-type and mutated cDNAs were cloned in eukaryotic expression vectors to obtain a fusion protein with green fluorescence protein (GFP); constructs were transfected in neonatal rat cardiomyocytes and in HL-1 cells. RESULTS: We identified two heterozygous mutations (c.304G>A (p.E102K) and c.1034T>C (p.I345T)) in two probands and in four family members. The two mutations p.E102K and p.I345T map to the N-terminal region, relevant to adhesive interactions. In vitro functional studies demonstrated that, unlike wild-type DSC2, the two N-terminal mutants are predominantly localised in the cytoplasm. CONCLUSION: The two missense mutations in the N-terminal domain affect the normal localisation of DSC2, thus suggesting the potential pathogenic effect of the reported mutations. Identification of additional DSC2 mutations associated with ARVC may result in increased diagnostic accuracy with implications for genetic counseling.


Assuntos
Displasia Arritmogênica Ventricular Direita/genética , Desmocolinas/genética , Mutação de Sentido Incorreto , Adolescente , Adulto , Animais , Células Cultivadas , Feminino , Triagem de Portadores Genéticos , Proteínas de Fluorescência Verde , Humanos , Masculino , Pessoa de Meia-Idade , Miócitos Cardíacos , Ratos , Transfecção
18.
Med Oncol ; 34(5): 85, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28391577

RESUMO

Neoadjuvant treatment in non-metastatic pancreatic cancer (PaC) has the theoretical advantages of downstaging the tumor, sterilizing any present systemic undetectable disease, selecting patients for surgery and administering therapy to each patient. The aim of this systematic review is to analyze the state of the art on neoadjuvant protocols for non-metastatic PaC. A literature search over the last 10 years was conducted, and papers had to be focused on resectable, borderline resectable (BLR) or locally advanced (LA) histo- or cytologically proven PaC; to be prospective studies or prospectively collected databases; to report percentage of protocol achievement and survival data at least in an intention-to-treat (ITT) analysis. Twelve studies were eligible for systematic review. Studies included a total of 624 patients: 248 resectable, 268 BLR, 71 LA and 37 non-specified. All studies were included for meta-analysis. ITT overall survival (OS) was 16.7 months (95% CI 15.16-18.26 months); for resected patients OS was 22.78 months (95% CI 20.42-25.16), and for eventually non-resected patients it was 9.89 months (95% CI 8.84-10.96). Neoadjuvant approaches for resectable, BLR and LA PaC are spreading. Outcomes tend to be better outside an RCT context, but strong evidences are lacking. Actually such treatments should be performed only in a randomized clinical trial setting.


Assuntos
Neoplasias Pancreáticas/terapia , Medicina Baseada em Evidências , Humanos , Terapia Neoadjuvante , Pancreatectomia/métodos , Neoplasias Pancreáticas/cirurgia
19.
Circulation ; 111(23): 3042-50, 2005 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-15939822

RESUMO

BACKGROUND: Three-dimensional electroanatomic voltage mapping offers the potential to identify low-voltage areas that correspond to regions of right ventricular (RV) myocardial loss and fibrofatty replacement in patients with arrhythmogenic RV cardiomyopathy/dysplasia (ARVC/D). METHODS AND RESULTS: Thirty-one consecutive patients (22 men and 9 women; mean age, 30.8+/-7 years) who fulfilled the criteria of the Task Force of the European Society of Cardiology and International Society and Federation of Cardiology (ESC/ISFC) for ARVC/D diagnosis after noninvasive clinical evaluation underwent further invasive study including RV electroanatomic voltage mapping and endomyocardial biopsy (EMB) to validate the diagnosis. Multiple RV endocardial, bipolar electrograms (175+/-23) were sampled during sinus rhythm. Twenty patients (group A; 65%) had an abnormal RV electroanatomic voltage mapping showing > or =1 area (mean 2.25+/-0.7) with low-voltage values (bipolar electrogram amplitude <0.5 mV), surrounded by a border zone (0.5 to 1.5 mV) that transitioned into normal myocardium (>1.5 mV). Low-voltage electrograms appeared fractionated with significantly prolonged duration and delayed activation. In 11 patients (group B; 35%), electroanatomic voltage mapping was normal, with preserved electrogram voltage (4.4+/-0.7 mV) and duration (37.2+/-0.9 ms) throughout the RV. Low-voltage areas in patients from group A corresponded to echocardiographic/angiographic RV wall motion abnormalities and were significantly associated with myocyte loss and fibrofatty replacement at EMB (P<0.0001) and familial ARVC/D (P<0.0001). Patients from group B had sporadic disease and histopathological evidence of inflammatory cardiomyopathy (P<0.0001). During the time interval from onset of symptoms to the invasive study, 11 patients (55%) with electroanatomic low-voltage regions received an implantable cardioverter/defibrillator because of life-threatening ventricular arrhythmias, whereas all but 1 patient with a normal voltage map remained stable on antiarrhythmic drug therapy (P=0.02). CONCLUSIONS: Three-dimensional electroanatomic voltage mapping enhanced accuracy for diagnosing ARVC/D (1) by demonstrating low-voltage areas that were associated with fibrofatty myocardial replacement and (2) by identifying a subset of patients who fulfilled ESC/ISFC Task Force diagnostic criteria but showed a preserved electrogram voltage, an inflammatory cardiomyopathy mimicking ARVC/D, and a better arrhythmic outcome.


Assuntos
Displasia Arritmogênica Ventricular Direita/diagnóstico , Técnicas Eletrofisiológicas Cardíacas/métodos , Adulto , Antiarrítmicos/uso terapêutico , Displasia Arritmogênica Ventricular Direita/terapia , Desfibriladores Implantáveis , Eletrocardiografia , Feminino , Humanos , Imageamento Tridimensional , Masculino , Miocárdio/patologia , Disfunção Ventricular Direita/fisiopatologia , Disfunção Ventricular Direita/terapia
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa